You should test your ad copy and creative assets (images & video) first. Audiences are rarely the reason something does not work on Facebook. Depending on your daily budget, test 2 pieces of ad copy against 3 - 5 images and see what sticks. If nothing works, then continue to test until you find what works. Hope you found this helpful, if so please click "like" below to let me know.
You might find it more efficient to use an app for the advertising of your Facebook campaigns. Advertising on Facebook can be a very time-consuming task and expensive task, especially if you don't have previous experience and no data history on your Facebook Pixel.
An app like AdScale can help you get started on the right track. It uses AI to analyze your store and match with similar stores in your industry to find and target the most relevant audience with the most suitable and high demand products that you have in your store. With or without the app, it will take time and initial expenses for a new Shopify store with no order history to start getting sales via Facebook Ads, since data need to be collected first to optimize the Facebook pixel. Nevertheless, AdSdcale can get you on the right track faster and effortlessly.
You can learn more about the app in this video: